Improve macos tabs accessbility support

Map PageTabList controls (i.e. QTabBar) to the TabGroup role, and
report the list of PageTabs as the tabs. Add a predicate-argument
to the unignoredChildren() function so that we can re-use that
logic to return the list of tabs, while also ignoring otherwise
accessible children, such as the scroll buttons.

Change-Id: I57472e9213dd178e018449e542de276051097073
Fixes: QTBUG-134807
Pick-to: 6.9 6.8
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

src/plugins/platforms/cocoa/qcocoaaccessibility.h

@@ -12,6 +12,8 @@
 
 #include "qcocoaaccessibilityelement.h"
 
+#include <functional>
+
 QT_BEGIN_NAMESPACE
 
 class QCocoaAccessibility : public QPlatformAccessibility
@@ -49,7 +51,9 @@ namespace QCocoaAccessible {
 NSString *macRole(QAccessibleInterface *interface);
 NSString *macSubrole(QAccessibleInterface *interface);
 bool shouldBeIgnored(QAccessibleInterface *interface);
-NSArray<QMacAccessibilityElement *> *unignoredChildren(QAccessibleInterface *interface);
+bool defaultUnignored(QAccessibleInterface *interface);
+NSArray<QMacAccessibilityElement *> *unignoredChildren(QAccessibleInterface *interface,
+                        const std::function<bool(QAccessibleInterface *)> &p = defaultUnignored);
 NSString *getTranslatedAction(const QString &qtAction);
 QString translateAction(NSString *nsAction, QAccessibleInterface *interface);
 bool hasValueAttribute(QAccessibleInterface *interface);

src/plugins/platforms/cocoa/qcocoaaccessibility.mm

@@ -122,6 +122,7 @@ static void populateRoleMap()
     roleMap[QAccessible::Separator] = NSAccessibilitySplitterRole;
     roleMap[QAccessible::ToolBar] = NSAccessibilityToolbarRole;
     roleMap[QAccessible::PageTab] = NSAccessibilityRadioButtonRole;
+    roleMap[QAccessible::PageTabList] = NSAccessibilityTabGroupRole;
     roleMap[QAccessible::ButtonMenu] = NSAccessibilityMenuButtonRole;
     roleMap[QAccessible::ButtonDropDown] = NSAccessibilityPopUpButtonRole;
     roleMap[QAccessible::SpinBox] = NSAccessibilityIncrementorRole;
@@ -200,6 +201,8 @@ NSString *macSubrole(QAccessibleInterface *interface)
         return NSAccessibilitySearchFieldSubrole;
     if (s.passwordEdit)
         return NSAccessibilitySecureTextFieldSubrole;
+    if (interface->role() == QAccessible::PageTab)
+        return NSAccessibilityTabButtonSubrole;
     return nil;
 }
 
@@ -249,14 +252,25 @@ bool shouldBeIgnored(QAccessibleInterface *interface)
     return false;
 }
 
-NSArray<QMacAccessibilityElement *> *unignoredChildren(QAccessibleInterface *interface)
+bool defaultUnignored(QAccessibleInterface *child)
+{
+    if (child && child->isValid()) {
+        const auto state = child->state();
+        return !state.invalid && !state.invisible;
+    }
+    return false;
+}
+
+NSArray<QMacAccessibilityElement *> *unignoredChildren(QAccessibleInterface *interface,
+                                    const std::function<bool(QAccessibleInterface *child)> &pred)
 {
     int numKids = interface->childCount();
 
     NSMutableArray<QMacAccessibilityElement *> *kids = [NSMutableArray<QMacAccessibilityElement *> arrayWithCapacity:numKids];
     for (int i = 0; i < numKids; ++i) {
         QAccessibleInterface *child = interface->child(i);
-        if (!child || !child->isValid() || child->state().invalid || child->state().invisible)
+
+        if (!pred(child))
             continue;
 
         QAccessible::Id childId = QAccessible::uniqueId(child);
@@ -269,6 +283,7 @@ NSArray<QMacAccessibilityElement *> *unignoredChildren(QAccessibleInterface *int
     }
     return NSAccessibilityUnignoredChildren(kids);
 }
+
 /*
     Translates a predefined QAccessibleActionInterface action to a Mac action constant.
     Returns 0 if the Qt Action has no mac equivalent. Ownership of the NSString is

src/plugins/platforms/cocoa/qcocoaaccessibilityelement.mm

@@ -1093,6 +1093,19 @@ static void convertLineOffset(QAccessibleTextInterface *text, int *line, int *of
     return nil;
 }
 
+// tabs
+
+- (NSArray *) accessibilityTabs {
+    QAccessibleInterface *iface = self.qtInterface;
+    if (iface && iface->role() == QAccessible::PageTabList) {
+        return QCocoaAccessible::unignoredChildren(iface, [](QAccessibleInterface *child){
+            return QCocoaAccessible::defaultUnignored(child)
+                && child->role() == QAccessible::PageTab;
+        });
+    }
+    return nil;
+}
+
 @end
 
 #endif // QT_CONFIG(accessibility)

tests/auto/other/qaccessibilitymac/tst_qaccessibilitymac.mm

@@ -66,6 +66,7 @@ QDebug operator<<(QDebug dbg, AXErrorTag err)
     bool axError;
 }
     @property (readonly) NSString *role;
+    @property (readonly) NSString *roleDescription;
     @property (readonly) NSString *title;
     @property (readonly) NSString *description;
     @property (readonly) NSString *value;
@@ -153,6 +154,21 @@ QDebug operator<<(QDebug dbg, AXErrorTag err)
     return arr;
 }
 
+- (NSArray *)tabs
+{
+    NSArray *arr;
+    AXError err;
+
+    if (kAXErrorSuccess != (err = AXUIElementCopyAttributeValues(reference, kAXTabsAttribute,
+                                                                    0, 100, /*min, max*/
+                                                                    (CFArrayRef *) &arr))) {
+        axError = true;
+        qDebug() << "AXUIElementCopyAttributeValue(kAXTabsAttribute) returned error = "
+                 << AXErrorTag(err) << "with reference" << reference;
+    }
+    return arr;
+}
+
 - (AXUIElementRef) findDirectChildByRole: (CFStringRef) role
 {
     TestAXObject *result = nil;
@@ -353,6 +369,7 @@ QDebug operator<<(QDebug dbg, AXErrorTag err)
 
 - (bool)                valid { return reference != nil; }
 - (NSString*)           role { return [self _stringAttributeValue:kAXRoleAttribute]; }
+- (NSString*)           roleDescription { return [self _stringAttributeValue:kAXRoleDescriptionAttribute]; }
 - (NSString*)           title { return [self _stringAttributeValue:kAXTitleAttribute]; }
 - (NSString*)           description { return [self _stringAttributeValue:kAXDescriptionAttribute]; }
 - (NSString*)           value { return [self _stringAttributeValue:kAXValueAttribute]; }
@@ -431,6 +448,7 @@ private Q_SLOTS:
     void checkBoxTest();
     void tableViewTest();
     void treeViewTest();
+    void tabBarTest();
 
 private:
     AccessibleTestWindow *m_window;
@@ -863,5 +881,57 @@ void tst_QAccessibilityMac::treeViewTest()
     [window release];
 }
 
+void tst_QAccessibilityMac::tabBarTest()
+{
+    QTabBar *tbar = new QTabBar;
+    static const unsigned int nTabs = 20;
+    for (unsigned int i = 0; i < nTabs; ++i)
+        tbar->addTab(QString::number(i));
+    tbar->setUsesScrollButtons(true);
+
+    m_window->addWidget(tbar);
+    QVERIFY(QTest::qWaitForWindowExposed(m_window));
+    QCoreApplication::processEvents();
+
+    TestAXObject *appObject = [TestAXObject getApplicationAXObject];
+    QVERIFY(appObject);
+
+    NSArray *windowList = [appObject windowList];
+    // one window
+    QVERIFY([windowList count] == 1);
+    AXUIElementRef windowRef = (AXUIElementRef)[windowList objectAtIndex:0];
+    QVERIFY(windowRef != nil);
+    TestAXObject *window = [[TestAXObject alloc] initWithAXUIElementRef:windowRef];
+    QVERIFY(window.valid);
+
+    // children of window
+    AXUIElementRef axTarBar = [window findDirectChildByRole:kAXTabGroupRole];
+    QVERIFY(axTarBar != nil);
+
+    TestAXObject *tb = [[TestAXObject alloc] initWithAXUIElementRef:axTarBar];
+    QVERIFY(tb.valid);
+
+    [appObject release];
+    [window release];
+
+    NSArray *tbChildList = [tb childList];
+    // +2 because of the scroll buttons
+    QCOMPARE([tbChildList count], nTabs + 2);
+
+    NSArray *tbTabsList = [tb tabs];
+    QCOMPARE([tbTabsList count], nTabs);
+
+    for (unsigned int i = 0; i < nTabs; ++i) {
+        AXUIElementRef axTab = (AXUIElementRef)[tbTabsList objectAtIndex:i];
+        QVERIFY(axTab != nil);
+
+        TestAXObject *tab = [[TestAXObject alloc] initWithAXUIElementRef:axTab];
+        QVERIFY(tab.valid);
+        QCOMPARE(QString::fromNSString(tab.role), QString::fromCFString(kAXRadioButtonRole));
+        QCOMPARE(QString::fromNSString(tab.title), QString::number(i));
+        QCOMPARE(QString::fromNSString(tab.roleDescription), "tab");
+    }
+}
+
 QTEST_MAIN(tst_QAccessibilityMac)
 #include "tst_qaccessibilitymac.moc"